This project stemmed from a program of research into the etiology of schizophrenia, conducted by Theodor Abelin, M.D., from 1967 to 1971, in the form of an "Epidemiologic Case History Study of Schizophrenia" (5-R01-MH13273) and an "Epidemiologic Family Study of Schizophrenia" (5- R01-MH16964). The major objectives and methods are: 1. To continue preliminary work done by this group in developing an automated system of observation of family interaction by testing its validity and reliability; a. through tests of its capacity to discriminate between behavior patterns of families of schizophrenics, nonschizophrenic mental hospital patients, and normal controls; and; b. through comparison of scores from the automated system with scores obtained by more usual methods of rating transcripts and tape recordings of the interaction sessions. 2. To test a number of formulations derived from theories of schizophrenia by operationalizing the relevant variables in the framework of the measures administered to families included in this study. This objective involves evaluation of performance in interaction situations and on individually administered tests, as well as comparison of the two sets of data.